1. Field of the Invention
The present invention relates to a plasma display, and more particularly, the present invention relates to a plasma display having improved heat sink efficiency and reduced manufacturing cost by including a heat sink for a Tape Carrier Package (TCP), or an Intelligent Power Module (IPM), etc., the heat sink being made of inexpensive graphite material having excellent thermal conductivity instead of an aluminum protective plate or a heat sink plate.
2. Description of the Related Art
A plasma display is a flat panel type display using a Plasma Display Panel (PDP). The PDP is produced by forming a plurality of electrodes on two substrates that are opposite to each other, arranging the substrates so as to be spaced apart from each other by a constant distance, and then sealing the substrates together after injecting discharge gases therebetween.
The plasma display includes the PDP and a plurality of drivers that are connected to each of the electrodes of the PDP.
Each pixel in the PDP is represented by a discharge in a pixel region. The discharge is generated by supplying a voltage to electrodes within a pixel space, so that a plasma or an excited state atom is produced. The power required for the discharge is partly dissipated as light, but mostly as heat.
The material of phosphors for forming the PDP have a disadvantage in that they are easily deteriorated and changed at high temperature, and their life shortened. By overheating, especially partial overheating in the PDP, a glass substrate can break due to stress caused by thermal expansion thereof.
The drivers, which are connected to the electrodes of the PDP, also dissipate a considerable amount of power in order to display a screen. The power dissipation results in thermal production. As a result, if the drivers are overheated, they can cause faulty operation. This faulty operation can cause deterioration in the quality of the screen. For example, a discharge can occur at a pixel which should not be discharged. Accordingly, it is very important to effectively radiate heat produced from the driver in the PDP. Since a considerable amount of heat is produced from a driving chip of the TCP, it is difficult to cool the driving chip if it does not contact a separate heat sink.
Usually, a chassis base, which is attached to a second surface of the PDP, is used to radiate heat from a heat generation part, such as the PDP and the drivers, to the outside. The chassis base is typically constituted by coupling a chassis-reinforcing member to a plate-type chassis base. The chassis-reinforcing member prevents deformation of the chassis base caused by external forces, and prevents the bending of the chassis base when the PDP is deformed by heat. As a result thereof, the deformation of the PDP may be also prevented. A driver for driving the PDP is arranged on a plurality of circuit substrates and mounted together with a power supply. The circuit substrate is usually spaced a constant distance apart from the chassis base through a boss, which is formed on the chassis base, in order for the ventilation of air.
The chassis base reinforces the mechanical strength by supporting the PDP and simultaneously receives heat from the PDP and the driver, which are in contact with the chassis base, and radiates the received heat to the outside. Additionally, the chassis base equally distributes the partly concentrated heat. For this reason, the chassis base is made of a metal, such as aluminum (Al), having excellent thermal conductivity.
However, the TCP and Chip On Film (COF) connect between the electrodes connected to the pixels of the PDP and drivers for driving the electrodes and have a built-in driving chip. Accordingly, a cooling problem of the driving chip occurs. Furthermore, an Intelligent Power Module (IPM) mounted on a driving board on a second surface of the chassis base includes a power transistor in one package, a protection circuit for protecting the power transistor, and a driving circuit for driving the power transistor. As a result thereof, the IPM produces a considerable amount of heat, and thus its cooling problem occurs.
Usually, a protection plate is mounted on an upper part of the TCP in order to protect the TCP and server as a heat sink of the TCP. The protection plate is usually made of aluminum. A protection plate made of aluminum has a disadvantage in that it is expensive and thus a manufacturing cost thereof is increased. Furthermore, a heat sink plate is mounted on an upper part of the IPM in order to serve as the heat sink of the IPM. The heat sink plate is also made of aluminum like the protection plate. Therefore, the protection plate made of aluminum has a disadvantage in that it is expensive and thus the manufacturing cost thereof is increased.